The common name "buffalo" has been used to describe North American Bison since Europeans first encountered the species, however, the term "buffalo" is more correctly applied to African and Asian water buffalo.

The largest native terrestrial mammal in North America is properly referred to as the American Bison.

Bison originated in Asia and spread into North America via the Bering land bridge at least 300,000 years ago. They have survived at least two major glaciations in North America. The primitive form, the Steppe bison, eventually evolved into the Modern American Bison (Bison bison), which is comprised of two races or subspecies - Wood Bison (Bison bison athabascae), adapted to open boreal woodlands,and Plains Bison (Bison bison bison), adapted to grassland habitat.

Note:

There is considerable academic discussion as to whether or not Wood Bison and Plains Bison are distinctly separate subspecies.

In these webpages, the content is primarily directed towards the woodland morph of the American Bison, the Wood Bison. If Wood Bison are not specifically indicated, or if the more general term "Bison" is used, then the information can be considered to refer to both Plains Bison and Wood Bison.

Before European colonization in the early 19th century, the Bison's range extended from the Peace River region in northeastern British Columbia, and the Great Slave Lake area in the Northwest Territories all the way to northern Mexico. Wood Bison occupied the western boreal forest regions and Plains Bison occupied the remainder of the habitat. The winter ranges of Wood and Plains Bison may have overlapped, but they probably did not share a common range during the breeding season.

Original and late-Holocene Range of Wood Bison in NW Canada

Based Upon Available Zooarchaelogical, Paleontological, Oral, and Written Historical Documentation

Bison once numbered about 30 million in North America, but with the westward movement of settlers, they were relentlessly slaughtered.

There is no way to estimate the historic abundance of Wood Bison in British Columbia. The entire population in Canada is thought to have numbered about 168,000 in the early 1800's. Uncontrolled hunting, particularly after 1860, led to a Canadian population low estimated at 250 by the turn of the century. This population decline also occurred in British Columbia, where the last confirmed Wood Bison from the primordial herd was shot near Ft. St. John in 1906.

Although legislation designed to protect Bison was passed in 1877 and 1893, enforcement was ineffective until after the turn of the century, when the Northwest Mounted Police were given responsibility for enforcing the Buffalo Protection Act in 1897 and formal patrols began in 1907. Populations began to recover outside of British Columbia, due to the protection of wild herds and the reintroduction of of Bison into former habitats, but Wood Bison in British Columbia remained extirpated.

To preserve Wood Bison habitat, Wood Buffalo National Park was established in 1922, and the total number of Wood Bison in the southern portion of their range was estimated at 1500-2000 individuals. Between 1925 and 1928, over 6,600 Plains Bison were translocated to Wood Buffalo National Park. These Plains Bison hybridized with the smaller Wood Bison population and introduced tuberculosis and brucellosis to the herd. The total Bison population in Wood Buffalo National Park did increase to about 12,000 by 1934, but Wood Bison as a distinct subspecies appeared to be disappearing.

In 1959, an isolated northern population of about 200 relatively pure Wood Bison within Wood Buffalo National Park was confirmed. A Wood Bison "salvage" operation to establish disease-free and genetically distinct Wood Bison herds began in the 1960's when individuals were moved to the Mackenzie Bison Sanctuary in the Northwest Territories, and to a fenced enclosure at Elk Island Provincial Park in Alberta. Most of the world population of Wood Bison is derived from the original 37 animals captured and relocated in the early 1960's.

During the 1970's, a large number of agencies and organizations formally recognized the plight of the Wood Bison. In 1975, a Canadian recovery program was established with representation from federal, provincial and territorial wildlife agencies and Parks Canada. In 1988, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designated Wood Bison as a threatened species.

The overall goal of the National-Provincial Wood Bison Recovery Team is the establishment of four healthy, free-roaming herds of 400 or more animals each within the historic Wood Bison range. Reintroduction of Wood Bison has resulted in disease-free herds in the Northwest Territories, Yukon Territory, British Columbia and Alberta.

Locations of Management Zones and Free Roaming Herds of Bison
in Northwestern Canada

Northwestern Canada contains a significant area of former Wood Bison range. Re-establishing herds of 400 or more genetically pure and disease free Wood Bison would be a major Canadian conservation success story.

Bison are gregarious, social animals. Throughout most of the year, they form herds composed primarily of adult females, subadults of both sexes, and calves. Mature bulls usually associate in smaller bachelor groups. Lone bulls are relatively common.

Groups of cows and bulls mix during the rutting season, which in northern areas may extend from July to September. Bison have lengthy gestation period of about 9 months. Cows and calves have a close relationship, which declines over time.

A single, reddish-brown calf, weighing 15-25 kg, is usually born between mid April and early June.

Calves can stand within about 10 minutes of birth, and can nurse within 30 minutes.

Calves nurse for at least seven to eight months.

The birth coat darkens to brownish black at about two months.

Calves grow rapidly and can weigh 135-180 kg by about eight or nine months.

In captivity, Wood Bison have been reported to live as long as 30 years, (one report shows 41 years) but in the wild, very few survive more than 20 years. Severe winters with deep snow, and mid winter thaws followed by severe freezing, result in winter caused mortality. Bison are vulnerable to predation by wolves, and in some populations, wolf predation can be a significant limiting factor to herd growth. In other herds, collisions with vehicles can be the limiting factor for successful herd growth. Severe spring storms may cause heavy calf mortality. An accidental cause of death can be drowning, which can often occur when animals fall through thin ice in the spring and fall.

Three significant diseases (anthrax, brucellosis, and tuberculosis) can affect wild populations of Bison. Brucellosis and tuberculosis are chronic diseases that reduce productivity and recruitment, cause dehabilitation, and make the animals vulnerable to predation. Anthrax is a highly infectious and often fatal disease. Anthrax spores may lie dormant for many years in the soil, only to cause epidemic outbreaks and significant mortality when environmental conditions are suitable. The animals in the free ranging Wood Bison herds in northwestern Canada are thought to be free of these infectious diseases.

Adaptations

Wood Bison are particularly suited to their niche as boreal grazers, and in northwestern Canada, the boreal grazer niche has been largely vacant since their extirpation.

In the north, where the snow can last for seven months and reach depths of over 1 m, grazing animals must develop special adaptations in order to survive successfully.

The Bison's unusual body shape, where the slim hindquarters appear out of proportion to the massive build and and heavy coat of the forequarters, is one adaptation to their need to forage through snow, a constant feature of their environment in winter.

Bison have spines on their upper vertebrae that can be up to 50 cm long in adult bulls. These spines support the large muscles that Bison use to employ the unique head-swinging action to clear away snow from their food. Although Bison feed almost entirely on grasses and sedges that are easily covered by snow, they can exist in ares where snow cover is too deep for most other ungulates.

Habitat

Bison change locations in response to seasonal changes in weather and food sources. Historically, wild herds of Plains Bison migrated long distances. In boreal forests, Wood Bison tend to have seasonal migrations of relatively short distances (< 20 km), but wandering mature bulls may travel 100 km or more. Wood Bison return to the same winter calving and breeding sites each year.

Wood Bison can be considered a keystone species in boreal forest ecosystems where suitable habitat conditions exist. They are capable of exploiting a unique niche of coarse grass and sedge meadows, including industrially disturbed sites such as roadsides.

In spring and early summer, Wood Bison utilize willow savanna and large open-prairies for calving and post-calving activities. During late summer and fall, they disperse into small groups for the rut, using forest stands for traveling between meadows, and they use wooded areas for summer shade and also for shelter in winter storms. However, they do little foraging in the forest. They often choose sandy ridges for wallowing.

Predators

Wolves are the most effective predators of northern Wood Bison, but both black and grizzly bears as well as wolves may prey on Bison calves.

Photos from: Carbyn, L.N., Oosenbrug, S.M., and Anions, D.W. 1993. Wolves, bison and the dynamics related to the Peace-Athabaska Delta in Canada's Wood Buffalo National Park. Circumpolar Research Series No. 4. Edmonton: Canadian Circumpolar Institute, University of Alberta.

Competition

Photo courtesy of Yukon Government

Within the historic range of Wood Bison, there is little dietary overlap between Wood Bison and other large ungulates.

There is some potential for minor components of Wood Bison diet to result in competition with other species for forage, providing that both species occur in the same area and the forage item is limiting.

Fall use of terrestrial lichens may overlap the forage needs of caribou, and spring browsing of willow may overlap the forage needs of moose. Wood Bison herds may indirectly influence predation rates on moose by supporting higher wolf densities than would exist without the presence of Wood Bison.

1963 - 18 animals transferred from Wood Buffalo National Park to the Mackenzie Bison Sanctuary, north of Great Slave Lake. Two animals died soon thereafter, and the remainng 16 animals became the foundation of the current herd.

1963-1987 - large population growth and range expansion

Highway 3 (Yellowknife Highway) runs through the middle of the herd’s range, with subsequent contributing mortality due to bison vehicle collisions

1988 - Regulated hunting implemented

1989 - ~2400 animals

2000 - 2000++ animals - this is the largest free ranging, disease free herd in Canada

2008 - 1600 animals

The population appears to be expanding its range to the west and northwest

Local flooding in the herd's former core range may be a contributing factor to its range expansion and increased numbers of animals on Highway 3.

Hunting is now permitted on the Highway 3 corridor to help address the number of bison vehicle collisions

The founding herd fragmented, and within a year of release, only 14 animals remained

1989 and 1998 - additional animals were added

Commonly seen in a typical winter habitat such as riparian balsam poplar forest, and mixed spruce-hardwood forests on islands in the Liard River

1989 release group uses more traditional habitat of mesic meadows, however, willow has encroached on the meadows and habitat may be a limiting factor for herd growth

1980-2002 - sporadic monitoring and research carried out

In 1998, a limited (2 animal) hunt was introduced, but little interest shown from the local population

Between June and September, there are reports of nuisance Wood Bison grazing in gardens, yards or on community airstrips in Fort Liard. Wallowing in unfenced sandy or dusty areas is also an issue.

2004 - Population estimated at ~404 animals, excluding calves

February 2011 - 6 females and 1 male were collared to allow biologists to learn more about their movements

March 2011 - Population estimated at ~413; bison were more widely distributed and observed over a larger area than had previously been observed. Some collared animals have moved to the west, up and down the Kotaneelee Valley. Collared and non-collared animals followed the Liard Highway corridor and used areas much further north than in past summers. Animals were observed as far north as Poplar River (km 220), and in the past they had rarely been seen north of Blackston (km 155).

The hunting quota has been increased to 7 animals, but still little interest shown from the local population

Recover free-ranging, genetically diverse, healthy wood bison throughout their historic range in the Northwest Territories (NWT), which can sustain on-going harvests for the benefit of all NWT residents

Contribute to the recovery of free-ranging, healthy wood bison throughout their historic range in Canada.

Key Strategies

Work with communities and Aboriginal governments to develop management plans for each bison population

Promote social, economic and cultural benefits for NWT residents

Maintain healthy and productive wood bison populations

Support wood bison recovery throughout its historic range

Actions taken on bison management since the adoption of the Management Plan include:

An increase in wood bison tags available for the Thcho region from three to 45 tags

An increase in wood bison tags available for the Nahanni population

Implementation of bison hunting along Highway 3

Information on reducing wildlife/vehicle collisions in other jurisdictions has been compiled

Increased ENR efforts to deter bison from communities

Workshops in communities towards developing this Strategy and management plans

The information below was presented at the Bison and Roads Committee meeting in December 2006, at Fort Nelson, BC, by Tom Jung, Senior Biologist, and Philip Merchant and Todd Powell, Yukon Territory, Department of Environment.

Can a reintroduction be too successful?

One of the main issues addressed by the 1998 Management Plan was the rapidly increasing size of the Aishihik herd. For this herd, the carrying capacity (number of individual animals that can be supported) was not defined by the ecological resources of their range, but rather by the "social carrying capacity", or tolerance, of local peoples to the presence of Wood Bison on the land.

Wood Bison had moved into areas where they were not welcome and caused damage that did not help in garnering support for their establishment and conservation.

Local First Nations supported the recovery team objective of maintaining a minimum viable population of Wood Bison in their traditional territories. However, there was not a lot of local support for allowing the herd to continue to grow and expand into new areas.

Diagram courtesy of Doug Urquhart

Community concerns:

Wood Bison invaded property and damaged important cultural sites (the cemetery at the Hutshi village)

Introduction of disease

Change in predator-prey relationships

More community concerns

Impact of Wood Bison on the valued moose and woodland caribou populations

Habitat overlap between Wood Bison, moose and caribou

How do you manage a nationally threatened, but locally abundant, species?

One solution might be "Conservation" Hunting

No predation or other controls on herd growth, coupled with community concerns about the impacts of this herd growth, led to the decision to establish a sport and subsistence harvest, carried out largely by Yukoners and the two First Nations, as the only means to limit herd size.

Hunting was implemented following community consultations (arising from the 1998 plan) as a means to keep the population within socially accepted limits.

This was not an easy decision, given the national status of Wood Bison as a threatened species, but options were limited and community concerns about the impacts needed to be addressed.

As this graph shows, harvest appears to be successful, thus far, in keeping the herd below 500 animals post-harvest, but above the national recovery goal of 400 animals.

Wood Bison are slowly weaving their way back into the cultural fabric of Yukoners. Many Yukon hunters that have learnt about and hunted Wood Bison have a new respect and value for the species. This is the most important long-term conservation gain of the hunt – and one that, ultimately, will likely create the public will to always maintain Wood Bison on the land.

Create a more favorable gender ratio (more cows and fewer bulls may lead to more moderate and manageable herd growth)

Revised bison hunting regulations were introduced in September 2008 in order to implement a new adaptive management framework. This adaptive management, which will be carried out on a 5 year trial basis, will give the Minister of Environment increased flexibility to make decisions regarding season dates, permit numbers, and to open subzones for hunting bison.

There will be an initial annual allowable harvest of 200 bison between December 1, 2008 and February 28, 2008.

Hay-Zama Bison Herd

Animals initially contained in a paddock, and scheduled to be released in 1988, but release was postponed in 1985 due to the risk of disease infection from Wood Buffalo National Park (WBNP) population

1993 - Bison escaped from the paddock through a broken fence and moved into the vicinity of the confluence of the Hay and Chinchaga Rivers

The Alberta government established a bison management area (BMA) in the northwestern portion of Alberta. Outside the BMA, Bison are not considered "Wildlife" under the Alberta Wildlife Act, and are not protected from hunting. The area between the BMA and WBNP serves as a buffer for the Hay-Zama herd against disease transmission

2008: 700++ individuals in Hay-Zama herd

Limited predation on herd

Range maps indicate good habitat in the area

Largest mortality factor for the herd is vehicle collisions

Hoping for a managed hunt in 2007/08 to control numbers.

Strong concern for herd dispersal and contact with tuberculosis and brucellosis infected bison from Wood Buffalo National Park ecosystem

News Release - The Fish and Wildlife Division of Alberta Sustainable Resource Development (ASRD), with endorsement of the National Wood Bison Recovery Team, is implementing a hunting season as an interim strategy to manage the Hay-Zama wood bison herd.

The Wood Bison hunt is being implemented to:

Control expansion of the Hay-Zama herd eastward, preventing contact with and contracting of diseases such as bovine brucellosis and tuberculosis from bison moving westward from Wood Buffalo National Park

Address public safety concerns within the communities of Chateh and Zama and along roads in the area. ASRD has responded to complaints of bison in communities and there have been several dozen vehicle collisions with bison on area roads resulting in property damage and the potential for serious injuries to people

Maintain Hay-Zama Wood Bison population at approximately 400 and limit distribution of these animals until diseased bison issues in and around Wood Buffalo National Park are successfully resolved

Biological samples from all harvested Wood Bison will be requested from all hunters, and used for disease testing.

The interim strategy to manage the Hay-Zama Wood Bison herd will be closely monitored. Future management plans will be based on the results from this interim strategy.

The information below was presented at the Bison and Roads Committee meeting in December 2006, at Fort Nelson, BC, by Mike Rowe, Biologist, and Dean Maclean, Senior Park Ranger, British Columbia Ministry of Environment, with input from Colin Leake, Public Works and Government Services Canada, and Roy Rea, University of Northern British Columbia.

The information collected by the Minstry of Environment on Wood Bison shows that all three BC herds are transboundary herds whose ranges overlap with either the Yukon (Nordquist herd), Northwest Territories (Nahanni herd), or Alberta (Etthithun herd). It is not clear whether the Hay-Zama herd from Alberta also range in BC.

Management goals for BC Wood Bison

Re-establish additional herds through translocation

Maintain separation from Plains Bison

Maintain disease free status

Allow populations to increase to sufficient levels to support consumptive and nonconsumptive use

Management concerns include:

Mortality due to vehicle collisions

Potential for interactions with domestic bison, with subsequent disease and genetic issues

1995 - 49 animals were transferred from Elk Island National Park, held in a temporary holding facility for two months, then released

January 2007 - Population estimated at 100 individuals; almost all individuals were on the Alaska Highway or right of way at the time of the 2007 count

February 2010 - roadside count yielded a maximum of 108 individuals

Expected to coalesce with the Nahanni herd

Nordquist herd management actions

5 GPS collars deployed on female bison in March 2009. The collars were fitted with reflective plating to make them more visible to motorists at night to increase human safety and reduce bison mortality. Many of the GPS collars deployed in March 2009 became inverted with the antenna pointing towards the ground. There is concern that this may reduce the life of the collars and result in fewer location fixes than expected.

Road-based classified counts were conducted between June 2009 and March 2010.

Salt blocks were placed in 2 different sites to encourage bison to remain away from the highway and in their calving areas near Nordquist Lake .

A series of prescribed burns within the Nordquist bison herd’s range were carried out and created ~1000 ha of early seral habitat, hopefully encouraging bison to spend more time away from the highway.

A large wildfire occurred near the Smith River, which burned 13,448 hectares within the Nordquist herd’s range during the summer of 2009.

Summer 1997 - the herd followed a road allowance 100 km south and joined an escaped feral herd of commercial bison. The mixed herd was captured, quarantined, disease tested and subsequently sold into private ownership. The concern was the loss of genetic distinctiveness of the Wood Bison subspecies. Funding from the sale was allocated to Wood Bison management in northeastern British Columbia.

1999-01 - In the second reintroduction attempt, 40 bison from Elk Island Provincial Park were released into an 850 ha paddock. The expected release was to be in 2004 or 2005, thereby ensuring they were imprinted on the release site, preventing southward travel to agriculturally developed areas.

2003 - The fence was breached, and the herd (49 individuals) became free ranging

May eventually link up with the Hay-Zama herd from Alberta

2006 - current population 124, with a growth rate of 14%

September 2009 - ~138 individuals

Management goals for Etthithun herd

Increase their geographic range, but limit southward migration

Increase overall numbers to 200 adults

Provide hunting opportunities

Etthithun herd management actions

5 GPS collars deployed on female bison in March 2009. The collars were fitted with reflective plating to make them more visible to motorists at night to increase human safety and reduce bison mortality. Many of the GPS collars deployed in March 2009 became inverted with the antenna pointing towards the ground. There is concern that this may reduce the life of the collars and result in fewer locations than expected.

Road-based classified counts were conducted between June 2009 and March 2010

Doig River First Nation was provided with a permit to hunt and kill up to 12 wood bison within the Etthithun herd’s range during 2009/10. The permit specified the area in which harvest could occur and was focussed on the southern portion of the herd range. The permit objective was to utilize harvest to modify the movement patterns of the herd to discourage them from using the southern portion of their range where they come into contact with agriculture. It was also hoped that hunting would make the animals more wary of humans to address issues of personal safety near the bison.

Pyric Herbivory in northeast BC

Pyric herbivory is defined as the ecological interactions between fire and grazing which result in shifting spatial patterns across the landscape. It is well documented that bison have a historical interaction with fire, meaning that their grazing patterns and movement across the landscape are greatly influenced by fire.

Following Wildfire 084 (located at Smith River, BC; with 13,448 ha burned within the Nordquist herd range), a Ph. D. research project was initiated to observe differences between grazed and ungrazed plant communities in burned environments. Randomly located exclosures that exclude large mammalian herbivores were constructed throughout the wildfire, in areas with similar fire severity and pre-burn stand composition. Vegetation composition and abundance will be compared between grazed (treated) and ungrazed (control) areas using analysis of variance, ordination, and multivariate techniques.

It is hoped that study of the relationships between fire and bison grazing behaviour will enable wildlife and land managers to:

Increase forage production and bison access to forage

Increase stand diversity and heterogeneity through differences in vertical structure

Reduce time Wood bison spend on roads and road right-of-ways in order to decrease vehicle-caused mortality

Pink Mountain Herd (Plains Bison)

In 1971, 48 imported and privately owned Plains Bison escaped into the wild, and formed the Pink Mountain herd

Herd has increased both its range and numbers

Latest population estimate is 1000++ animals, ranging over 2,000 km2

The Pink Mountain herd is the largest free ranging, tuberculosis and brucellosis free Plains Bison herd in North America

Generally confined to the grass/sedge meadows in the upper Sikanni and Halfway River valleys

Potential exists for competition between the free roaming Plains Bison Pink Mountain herd and Wood Bison if the ranges should overlap.

The presence of this free roaming, feral Plains Bison herd jeopardizes the Wood Bison herd at Etthithun Lake and can potentially comprise Wood Bison recovery efforts in Alberta, the Northwest Territories, and the Yukon.